Pre-clinical disability is an early warning system in the disablement process as it is characterized by selecting to perform everyday tasks less often and compensating for those tasks still being performed. This phase serves as an ideal target for preventative strategies because treatments can be designed for individuals on the verge of disability thus interrupting the occurrence of outright disability. One such strategy that optimizes the transfer of adaptations to real-life situations is task-specific exercise (TSE). This type of intervention holds promise to determine how pre-clinically disabled older adults might interrupt the disablement process and instead begin an enablement process and thus lead us to better interventions to treat and prevent disability from occurring. However, because of the complexity of the disablement process, it has been extremely challenging to objectively identify outcomes that represent changes in selection, optimization, and compensation of tasks (the SOC domains). The objective of the current application is first, to ask what are the short and long-term responses of TSE in the pre-clinically disabled older adults (aged 60+ years) using a single-masked randomized controlled design. Second we seek to refine and validate our outcomes using non-invasive monitoring of SOC domains with the Intelligent Device for Energy Expenditure and Activity (IDEEA). Thirdly, we will shed exciting new light on whether TSE alters neuromechanical and psychological factors. We want to know this, in part, from a mechanistic perspective to gain insight into the processes by which TSE improves disablement outcomes. Also, this will help us to better understand how to enhance the TSE intervention to treat pre-clinically disabled patients. Thus, we offer two hypotheses: Hypothesis #1: TSE increases selection and optimization of everyday tasks, while reducing compensation to achieve task performance. Hypothesis #2: TSE mediates changes in SOC domains through both neuromechanical (decrease variability of movement and increase muscle work capacity) and psychological (increased confidence to perform tasks and increased executive function) properties. These data are expected to guide us in designing a randomized controlled trial that will test whether TSE in the pre-clinically disabled can reduce future incidence of outright disability. PUBLIC HEALTH RELEVANCE: The proposed project will develop a trajectory of research that will identify individuals on the version of physical disability and intervene with exercises specifically designed to improve everyday task performance. This research is highly relevant to the public health as it will build evidence for extending the capacity to live independently.